People joining and never responding problem

I am running a pick up game and typically have 3 random people join the group, but never actually jump in the game. They do not respond to any messages I send them. Is this common? Is there something I am doing wrong that isn't making it clear how to join?

Welcome to the Interwebs, where 50 to 75% of the people don't actually exist.

There's probably an issue with people not knowing how the games work. However there's no info on what you need to do or how it will work, especially when you see games for lots of players. I think a Utube of a stream would be helpful. Maybe some screen shots in the description and at least info on whether you need to bring a character what level etc. I am tempted to join a game but wouldn't want to disrupt it. I expect some people are joining and lurking just to see what's involved.

No one is lurking, I would see their icon. No one is responding to messages, but I suspect they may not see the indicator saying they have a message. I have an, albeit brief, explanation in the chat area below the game, but again they may not see that. I will try updating the base description though, thanks